Ivan, Patrick,
Yes-- you can use Envirotex to get this effect, however, if you look closely at the photo, this is probably a fairly shallow pour, as it appears to be for a single figure (fantasy?) and only covers the feet. By the shape of the pour, it looks like the builder used a small shallow box with rounded corners to do the pour too-- likely a small plastic open top box, sprayed with some type of mold release or carefully lined with some type of wax paper. He either pried the base out of the box when cured, or carefully cut it away. This looks like a single pour to me.
VR, Russ